摘要:

Horn antennas with dielectrically-filled longitudinal corrugations have recently been presented, and have been referred to as hard horns. Cylindrical hard horns can support a TEM wave at the design frequency, providing uniform aperture distribution and zero cross polarisation: this makes them attractive to use as compact elements in cluster feeds. In the paper the characteristic equation of a square hard waveguide is presented, and the crosspolar bandwidth is determined.

DOI:10.1049/ip-h-2.1988.0056

出版商:IEE    

年代:1988

数据来源: IET

摘要:

Junction circulators using finline circuits may be realised by employing planar or turnstile ferrite resonators. The paper describes a finline turnstile circulator at 21 GHz, comprising a directly coupled evanescent junction of three E-plane WR42 waveguides symmetrically loaded byH–plane open gyromagnetic resonators. The degenerate counter-rotating eigenvalues of the device correspond to the even solution of two coupled quarterwave long resonators; the junction is separately cut-off for the in-phase eigenvalue.

DOI:10.1049/ip-h-2.1988.0057

出版商:IEE    

年代:1988

数据来源: IET

摘要:

A dielectric waveguide branching directional coupler with curved transtion is presented, and is investigated by the use of a staircase approximation, which combines the building block approach of multimode network theory with a rigorus mode matching procedures. The coupling problem is analysed from the view point of the scattering of incident surface waves by the nonuniform dielectric structure as a whole. Particular attention is given to establishing the effect of radiatioin due to bending of the curved transtion wave guides and other discontinuties on the performance of the coupler. Numerical Results are given, from which guidelies for the design of bidirectional couples are derived

DOI:10.1049/ip-h-2.1988.0058

出版商:IEE    

年代:1988

数据来源: IET

摘要:

An alternative nonlinear method to calibrate the six-port reflectometer is developed. Using this method four standards and iteratrive procedure are needed to calibrate the reflectometer.Experimental results show that this method coverges very rapidly, provides a good accuracy in calibration parameters and at the same time avoids degenerate solutions which produce unwanted singularities in the mesurement.

DOI:10.1049/ip-h-2.1988.0059

出版商:IEE    

年代:1988

数据来源: IET